This invention relates to the art of effecting heat transfer between the perimeter of a rotary roll and a web travelling in contact with the perimeter, and is more particularly concerned with improvements attaining control of the heat transfer capability throughout the length of the heat transfer roll.
Uniform transfer of heat from a rotating roll to a web is required in many applications, both within and outside of the paper industry. Sometime adjustable or differential heat transfer along the length of the roll may be required for special applications. Numerous attempts have heretofore been made to attain these ends, some employing very complex mechanical designs, and others more simple designs. Representative of the present state of the art are the following U.S. Pat. Nos.: 2,677,899; 2,697,284; 2,919,904; 2,956,348; 3,838,734-all disclosing relatively simple heat transfer roll arrangements but without the fluid distribution control capability of the present invention.
U.S. Pat. Nos.: 3,224,110; 3,309,786; 3,419,068; 3,581,812; 3,633,662; 3,643,344; 4,120,349-all disclose more complex arrangements, but without the fluid distribution controlling capability of the present invention.
More particularly, none of the listed patents provides for the control of roll edge temperature, that is the temperature at the opposite extremities of the outer or web contacting perimeter of the shell of the roll assembly, relative to or in combination with the heat transfer temperature of the greater intermediate portion of the heat transfer perimeter of the roll.